Tab Welding Structure and Battery

Disclosed are a tab welding structure and a battery. The tab welding structure includes a tab and a to-be-welded part, where the to-be-welded part is welded on the tab to form a connecting portion, a plurality of first welding mark structures that are concave in a thickness direction of the connecting portion are formed on the connecting portion, each of the plurality of first welding mark structures includes a first welding surface and a first surrounding wall that are connected to each other, and the first surrounding wall is an arc surface.